Tension release packer for a bottomhole assembly

Abstract

A resettable elastomeric packer element of a packer, compressed for sealing in a wellbore, is released from sealing engagement in the wellbore by applying tension to an end of the packer element. The elastomeric packer element stretches and releases from the wellbore forming an annular passageway between the packer element and the wellbore. In the absence of a pressure equalization valve or flow passages through the packer, the annular passageway equalizes pressure differentials across the packer element allowing a tool, in which the packer is incorporated, to be moved in the wellbore with little or no damage to the packer element and further, allows debris to flow from above the packer to below the packer.

The embodiments in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A method for completing a wellbore comprising:
 running a completion tool, having a releasable packer therein, into the wellbore, the releasable packer having
 an annular elastomeric sealing element; 
 an anchor for anchoring the sealing element in the wellbore; and 
 a mandrel and a housing, the mandrel being axially and telescopically moveable within the housing, the elastomeric sealing element being positioned circumferentially about the mandrel and connected at least at a pull end thereof; 
 
 locating the sealing element below a zone of interest in the wellbore; 
 axially compressing the elastomeric sealing element into sealing engagement with the wellbore and actuating the anchor by moving the mandrel axially toward the housing; 
 treating the zone of interest above the compressed elastomeric sealing element, creating a pressure differential across the sealing element, and thereafter; 
 applying axial tension to the pull end of the elastomeric sealing element for radially retracting at least the pull end thereof by moving the mandrel axially away from the housing for forming an annular passageway between the elastomeric sealing element and the wellbore, allowing pressure thereabove to equalize with pressure therebelow, for releasing the packer from sealing engagement with the wellbore. 
 
     
     
       2. The method of  claim 1  wherein the mandrel is uphole of the housing and the pull end is an uphole pull end, releasing the packer comprising:
 pulling the mandrel uphole for applying tension to the uphole pull end of the elastomeric sealing element for releasing the elastomeric sealing element from the wellbore. 
 
     
     
       3. The method of  claim 2  wherein the elastomeric sealing element is connected to the mandrel by an uphole ring secured to the uphole pull end of the elastomeric sealing element, releasing the packer comprising:
 pulling the mandrel and connected uphole ring uphole for releasing the elastomeric sealing element from the wellbore. 
 
     
     
       4. The method of  claim 3  wherein the housing supports a compression ring, compressing the packer element comprising:
 moving the mandrel, the connected uphole ring and the packer element toward the compression ring for compressing the elastomeric sealing element therebetween. 
 
     
     
       5. The method of  claim 1 , when the packer is released, further comprising:
 flowing debris through the annular passageway from above the elastomeric sealing element to below the elastomeric sealing element. 
 
     
     
       6. The method of  claim 1  wherein the pull end is an uphole pull end, further comprising:
 biasing the uphole pull end of the elastomeric sealing element, a downhole end of the elastomeric sealing element, or both, radially inwardly. 
 
     
     
       7. The method of  claim 1 , wherein the anchor further comprises a set of slips supported by the housing and a cone operably connected to the mandrel between the annular packer element and the housing and wherein moving the mandrel axially toward the housing further comprises:
 moving the cone towards the slips; 
 engaging the cone with the slips; and 
 radially extending the slips into engagement with the wellbore. 
 
     
     
       8. The method of  claim 7 , wherein the elastomeric sealing element is connected to the mandrel by an uphole ring secured to an uphole pull end of the elastomeric sealing element. 
     
     
       9. The method of  claim 3  wherein the uphole ring is connected to the mandrel by threads. 
     
     
       10. A method of equalizing pressure above and below a compressible, annular sealing element of a packer, the packer having
 a mandrel and a housing; 
 the mandrel being axially and telescopically moveable within the housing; 
 the annular sealing element being positioned circumferentially about the mandrel; and 
 a pull end being secured thereto, 
 
       set within a wellbore for sealing therebelow, comprising:
 applying axial tension to the pull end of the annular sealing element for radially retracting at least the pull end by moving the mandrel axially away from the housing for forming an annular passageway between the annular sealing element and the wellbore, releasing the annular sealing element from sealing therein, 
 wherein pressure above and below the elastomeric sealing element is equalized through the annular passageway. 
 
     
     
       11. The method of  claim 10  further comprising:
 flowing debris through the annular passageway from above the annular sealing element to below. 
 
     
     
       12. The method of  claim 10  wherein the pull end is secured to the mandrel by threads. 
     
     
       13. A method for protecting a compressible, annular sealing element of a packer in a tool, the packer having
 a mandrel and a housing; 
 the mandrel being axially and telescopically moveable within the housing; 
 the annular sealing element being positioned circumferentially about the mandrel; and 
 a pull end being secured thereto, 
 
       set within a wellbore and having a pressure differential thereacross, prior to moving the tool within the wellbore, comprising:
 applying axial tension to the pull end of the annular sealing element by moving the mandrel and pull end axially away from the housing for release from the wellbore for radially retracting at least the pull end for forming an annular passageway between the annular sealing element and the wellbore for equalizing pressure above and below the annular sealing element; and thereafter moving the tool in the wellbore. 
 
     
     
       14. The method of  claim 13 , wherein the pull end is an uphole pull end, further comprising:
 biasing the uphole pull end of the annular sealing element, a downhole end of the annular sealing element, or both, radially inwardly. 
 
     
     
       15. The method of  claim 13  wherein the pull end is secured to the mandrel by threads. 
     
     
       16. A pressure equalization tool for use in a wellbore comprising:
 a tubular housing having a bore therethrough; 
 a mandrel fit to the bore of the housing and being telescopically and axially moveable therein; 
 an elastomeric, annular packer element fit concentrically about the mandrel and connected at a pull end thereto; and 
 an anchor for anchoring the housing in the wellbore, 
 wherein when the mandrel and annular packer element are moved axially toward the housing, the anchor is set and the annular packer element is compressed therebetween into sealing engagement with the wellbore for sealing an annulus between the mandrel and the wellbore; and 
 wherein when the mandrel and annular packer element are pulled axially away from the housing, the annular packer element is pulled axially into tension for radially retracting at least the pull end for release from sealing engagement with the wellbore, forming a fluid passageway in the annulus for fluid communication past the annular packer element for equalizing pressure thereacross. 
 
     
     
       17. The pressure equalization tool of  claim 16  wherein the pressure equalization tool is in a completion tool for completing the wellbore in a formation, further comprising:
 a tubular member, the mandrel extending axially between the tubular member and the tubular housing; 
 one or more fluid ports in the tubular member; 
 wherein when the annular packer element is in sealing engagement with the wellbore for isolating the annulus therebelow, fluid is delivered from the fluid ports to a zone of interest above the annular packer element; and 
 wherein when the annular packer element is released from sealing engagement with the wellbore, the tool is freely movable within the wellbore to another zone of interest or to surface. 
 
     
     
       18. The pressure equalization tool of  claim 16  further comprising:
 a ring operatively connected to the mandrel to which the pull end of the annular packer element is secured, 
 wherein the ring, when moved axially by the mandrel away from the housing, applies tension to the annular packer element; and when moved axially by the mandrel toward the housing, compresses the annular packer element. 
 
     
     
       19. The pressure equalization tool of  claim 18  wherein the ring is a steel ring, secured to the elastomeric annular packer element by elastomeric bonding, mechanical bonding or both. 
     
     
       20. The pressure equalization tool of  claim 16  wherein the elastomeric annular packer element further comprises:
 one or more circumferentially extending springs embedded therein adjacent an upper end, adjacent a lower end or both. 
 
     
     
       21. The pressure equalization tool of  claim 16  further comprising:
 a compression ring supported by the housing, the annular packer element being compressed thereagainst when the mandrel is moved axially toward the compression ring. 
 
     
     
       22. The pressure equalization tool of  claim 21  wherein a trailing end of the packer element is secured to the compression ring. 
     
     
       23. The pressure equalization tool of  claim 16  wherein the anchor comprises:
 a set of slips supported by the housing; and 
 a cone operatively connected to the mandrel between the annular packer element and the housing, the cone being axially moveable between the mandrel and the slips, for radially extending the slips into engagement with the wellbore, when the mandrel is moved axially toward the housing to compress the annular packer element. 
 
     
     
       24. The pressure equalization tool of  claim 23  wherein the cone acts as a compression ring against which the annular packer element is compressed when the mandrel is moved axially toward the housing. 
     
     
       25. The pressure equalization tool of  claim 23  further comprising:
 an annular upset formed on the mandrel; and 
 a release shoulder formed in the cone, 
 wherein when the mandrel has moved axially away from the housing and released the annular packer element, the annular upset engages the release shoulder on the cone for moving the cone axially therewith and releasing the slips. 
 
     
     
       26. The pressure equalization tool of  claim 18 , further comprising:
 a first shoulder extending radially outwardly from the mandrel; and 
 a second, opposing shoulder extending radially inwardly from the ring, 
 wherein when the mandrel is moved axially away from the housing to release the annular packer element, the first shoulder on the mandrel engages the second shoulder on the ring for applying tension to the annular packer element. 
 
     
     
       27. The pressure equalization tool of  claim 26 , further comprising a third shoulder spaced from the first shoulder,
 wherein when the mandrel is moved axially toward the housing, the third shoulder engages a radial surface of the ring for axially moving the ring and the annular packer element secured thereto, for compressing the annular packer element therebetween. 
 
     
     
       28. The pressure equalization tool of  claim 16  wherein the annular packer element is compressed between the pull end of the annular packer element and the anchor. 
     
     
       29. The pressure equalization tool of  claim 16  wherein the anchor is situate between the annular packer element and the housing. 
     
     
       30. The pressure equalization tool of  claim 18  wherein the ring is operatively connected to the mandrel by threads. 
     
     
       31. The pressure equalization tool of  claim 26  wherein the anchor comprises:
 a set of slips supported by the housing; and 
 a cone operatively connected to the mandrel between the annular packer element and the housing, the cone being axially moveable between the mandrel and the slips, for radially extending the slips into engagement with the wellbore, when the mandrel is moved axially toward the housing to compress the annular packer element. 
 
     
     
       32. The pressure equalization tool of  claim 31  further comprising:
 an annular upset formed on the mandrel; and 
 a release shoulder formed in the cone, 
 wherein when the mandrel has moved axially away from the housing and released the annular packer element, the annular upset engages the release shoulder on the cone for moving the cone axially therewith and releasing the slips.